1. Field of Invention
The present invention is directed to a printing method and a printing medium wherein the printed area thereof is essentially or totally free of mottle. More particularly, the present invention is directed to a color printing method and a paper medium, which is substantially or totally resistant to mottle formation in a color printed region thereof or wherein mottle is minimized.
2. Description of Related Art
Mottle is a condition relating to a printed region, usually on paper. Typically the printed region is a continuously colored area having deposited thereon one or more colors. For example, color prints (e.g., those made by xerographic printing) contain numerous such contiguously colored areas forming the print itself. Typically, mottle displays itself as a variation of color density in the printed field. For example, when viewed by the naked eye, mottle manifests itself as areas of light and heavy color density. Thus, instead of viewing uniform color density, a variation in the color density is noticed. As a result, such mottle detracts from the overall print quality.
Mottle is typically observed in color printing. When the printing color is monotone black, the presence of mottling, though present, can be overcome by masking the underlying mottle with extra layers of black ink. However, in color printing, it is often difficult to simply increase the color layer thickness. This is partly true because in color xerography, for example, it is not effective to increase the color thickness and yet maintain a given suitable color density.
Among other properties, color density, color saturation and color gamut depend on a precisely defined set of cyan, magenta, yellow and black color densities. Further, fusing energy, toner adhesion and image gloss depend on the amount of a given color toner deposited per unit area printed. As such, if the thickness of the color layer is increased to a level sufficient to mask, reduce or otherwise eliminate mottle, the desired color saturation, the color gamut, the color itself, the image gloss and the like, respectively, cannot be maintained. Thus, a need exists for providing a method of printing and a print medium that is substantially or totally resistant to mottle formation without having to increase color thickness.